Light source apparatus

Abstract

A light source apparatus includes first and second light sources having different maximum light amounts used, a first light amount detection section detecting a light amount of first light of the first light source, a second light amount detection section detecting a light amount of second light of the second light source, a light amount limiting section limiting a light amount of light incident upon the second light amount detection section so that light amounts detected in the first light amount detection section and the second light amount detection section match a predetermined value within a detection range when light with the maximum light amounts used are emitted from the first light source and the second light source, and a control section controlling amounts of light emission of the first light source and the second light source based on detection results of the first and second light amount detection sections.

What is claimed is: 
     
       1. A light source apparatus comprising:
 a first light source that emits first light at a first light amount as a maximum light amount of the first light source; 
 a second light source that emits second light at a second light amount as a maximum light amount of the second light source, the second light amount being higher than the first light amount; 
 a first light amount detection section provided on an optical path of the first light and configured to detect a light amount of the incident first light; 
 a second light amount detection section having a detection range identical to a detection range of the first light amount detection section, provided on an optical path of the second light, and configured to detect a light amount of the incident second light; 
 a light amount limiting section that limits a light amount of light incident upon the second light amount detection section based on a position and an optical axis direction of each of the first light source and second light source and on a position and an angle of an incident surface of light of each of the first light amount detection section and the second light amount detection section so that the light amounts detected in the first light amount detection section and the second light amount detection section match a predetermined value within the detection range when light with the first light amount and light with the second light amount are emitted from the first light source and the second light source; and 
 a control section that controls amounts of light emission of the first light source and the second light source based on detection results of the first and second light amount detection sections, 
 wherein the light amount limiting section determines an attenuation factor of the amount of light incident upon the second light amount detection section based on a product of a light emission ratio and a sensitivity ratio, the light emission ratio being a ratio between the amount of light emission of the second light source and the amount of light emission of the first light source, the sensitivity ratio being a ratio between a spectral sensitivity of the second light amount detection section and a spectral sensitivity of the first light amount detection section. 
 
     
     
       2. The light source apparatus according to  claim 1 ,
 wherein the light amount limiting section determines an attenuation factor of light based on a relationship between a first light emission ratio which is a ratio of an amount of light emission of the first light source to a reference light amount and a spectral sensitivity characteristic of the first light amount detection section and a relationship between a second light emission ratio which is a ratio of an amount of light emission of the second light source to the reference light amount and a spectral sensitivity characteristic of the second light amount detection section. 
 
     
     
       3. The light source apparatus according to  claim 1 ,
 wherein the light amount limiting section comprises a neutral density filter. 
 
     
     
       4. The light source apparatus according to  claim 3 ,
 wherein the light amount limiting section comprises a wavelength filter that allows the second light amount detection section to pass only light of a color to be detected. 
 
     
     
       5. The light source apparatus according to  claim 2 ,
 wherein the light amount limiting section comprises a slit in which an opening in a size based on the light emission ratio is formed. 
 
     
     
       6. The light source apparatus according to  claim 1 ,
 wherein the light amount limiting section comprises a light guide member that transmits light to be detected to the second light amount detection section, a light transmission characteristic of the light guide member being adjusted so that the light amounts detected in the first light amount detection section and the second light amount detection section match the predetermined value within the detection range when the light of the first light amount and the light of the second light amount are emitted from the first light source and the second light source. 
 
     
     
       7. The light source apparatus according to  claim 6 ,
 wherein the light guide member is a light guide fiber and at least one of a diameter and a length of the light guide fiber is adjusted as the light transmission characteristic. 
 
     
     
       8. The light source apparatus according to  claim 1 ,
 wherein the first and second light amount detection sections comprise color sensors capable of detecting light amounts of a plurality of light beams. 
 
     
     
       9. The light source apparatus according to  claim 1 ,
 wherein the control section controls amounts of light emission of the first light source and the second light source based on detection results of the first light amount detection section and the second light amount detection section, a light amount of which is limited by the light amount limiting section.